With the present day advancement of high-bandwidth communication infrastructure and the widespread acceptance of digital video compression standards, there has been an increasing demand for video-based services. Among these new and expanding services are long distance education, surveillance systems, video-on-demand, interactive video games and video conferencing. Importantly, these and other future video-based services will need cost-effective and efficient video data processing and transmission systems and methods.
A typical multi-windows display system will display multiple video sequences to a video user. The windows environment allows the user to simultaneously view several video sequences or images originating from several different sources. However, prior art multiple window display systems have made inefficient use of bandwidth. Moreover, prior art multiple window display systems have needed complex encoding and decoding systems and methods, which are both costly and have significant processing delays.
In the case of digital image transmission applications, such as digital television, it has often been necessary to compress the image data in order to conserve bandwidth. In this regard, a frame of video (i.e., one full screen) may be composed of an array of at least 640.times.480 pixels. A video sequence is composed of a series of frames. In order to obtain a standard quality video sequence, a frame rate of at least 24 frames per second is necessary. To transmit this quantity of image data using the available bandwidth, various well known compression techniques have been employed. These compression techniques typically take advantage of pixel image data repetition, known as spacial correlation. Spacial correlation occurs when several adjacent pixels have the same or similar brightness and color values. Data compression techniques take advantage of this repetition by transmitting the brightness and color data from one pixel and transmitting information on the number of following pixels for which the data is identical, or by transmitting only the brightness and color data "difference" between adjacent pixels. Several video compression standards have become widely adopted, including MPEG1, MPEG2, JPEG and px64. However, it should be appreciated that in some situations compression alone does not reduce bandwidth consumption as much as desirable. Therefore, there is a need to further reduce bandwidth consumption.
Prior art multiple window display systems have also failed to address the problem of complex and costly encoding, decoding and other needed video process systems. In this regard, prior art systems do not encode the final display location of the video data at the receiving location. As a result, the decoding is made more complex, since the display information must be re-coded with the proper display location.
The present invention overcomes these and other drawbacks of prior art systems.